Generally an abusive, scheming, manipulative exploitative person with very poor judgement of value in life.
The expression is not limited to either gender, and the recipient can be alive or dead.
E.g." Thatcher..she was a total cunt! ", or , Cameron; not only is he a nobhead and wanker, but also a 'total cunt'.
To be used with caution so as not to dilute its meaning!